This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Axonal transport is a process in which membrane bound particles are in transit along microtubules powered by motor proteins belonging to the kinesin and cytoplasmic dynein superfamilies. Recently we identified a Kinesin-3 (KIF1A) that co-purifies with axoplasmic organelles and localizes to organelle/microtubule interfaces. Antibodies raised against Kinesin-3 decorate 100 nm organelles in extruded axoplasm and inhibit organelle transport towards the plus ends of microtubules. These finding suggest that Kinesin-3 may be responsible for moving 100 nm organelles towards the plus ends of microtubules. Here, we propose to characterize the motor properties of purified Kinesin-3 and to identify the molecular anatomy of the Kinesin-3 cargo. Understanding the rate and direction of Kinesin-3 movement and the molecular composition of its cargo will help establish the role of Kinesin-3 in the axon and determine it's contribution to motor mediated transport.